Blink: The Power of Thinking Without Thinkingby Malcolm Gladwell304pp, Allen Lane, £16.99

This second book by the world's top journalist/business guru, makes a very attractive proposition. If we pay attention to his findings, Malcolm Gladwell says, we can learn to make better snap judgments. Which is inviting, as we'd all like to make the correct decisions quickly, and also generous on Gladwell's part. Offers of this life-improving kind, whether they relate to deficient memory or crippling social embarrassment, usually feature in the bottom righthand corner of newspaper front pages, accompanied by a picture of a sad-looking man and demands for large sums of money in exchange for an unpromising programme of patent exercises.

Gladwell, in contrast, asks only a modest £16.99 for Blink, an entertaining, undemanding study of first impressions which offers to unlock the innate decisiveness of any reader who reaches page 265. "The first task of Blink is to convince you of a simple fact", Gladwell writes: "decisions made very quickly can be every bit as good as decisions made cautiously and deliberately." In which case, the reader may ask, how come there are so many quick but bad decisions? Gladwell is ahead of us. "Answering that question is the second task of Blink." And how do we ensure that our quick decisions are always good? Simple: read more Gladwell. "The third and most important task of this book is to convince you that our snap judgments and first impressions can be educated and controlled. I know that's hard to believe."

Anyone who has suffered under the Atkins regime may feel familiar with the faintly hucksterish, overly-helpful tone of Gladwell's introduction. "You've bought this book, haven't you?", Dr Robert C Atkins demands those of us who did, indeed, pay for the cramps and stinking breath which are the legacy of his New Diet Revolution. "How long did you first hold it in your hands?" is Gladwell's question for the people who bought Blink. "Two seconds? ... Aren't you curious about what happened in those two seconds?" With his brazen brand-repetition, over-familiarity and unlikely visions of the new, improved life that awaits the Blink alumnus, the younger guru repeatedly echoes the literary style of the late dietician, who liked to goad fatties with glimpses of the glorious rewards of dietary compliance: "My goal is to make you become a healthy and happy person and to show you how to stay that way."

Gladwell, from his loftier perch, on the staff of the New Yorker, is no less eager to anticipate doubters, the better to prod them towards enlightenment. Can instant reactions really be inculcated? Most certainly. "The power of knowing, in that first two seconds, is not a gift given magically to a fortunate few. It is an ability that we can all cultivate." And if more of us did it, Gladwell believes, "we would end up with a different and better world".

But what's in it for him? This is not, admittedly, a question one would routinely put to an eminent contributor to the New Yorker, but his salesmanlike pitch is apt to elicit a matching, customer-like suspicion. Perhaps Gladwell simply believes that endless reiteration of Blink's brilliant, life-changing potential is essential if it is to live up to his last bestseller, The Tipping Point, and thus enhance his new career as the unworldly, barefoot thinker the business community really trusts. Since The Tipping Point became the market analyst's bible, Gladwell has been lecturing the staff of Nike, Microsoft and many others, charging $40,000 an appearance. So Blink is a self-help book. Never mind what happens to our lives; will Blink enhance Gladwell's?

Since it features some likely-looking jargon and various marketing anecdotes, it may well delight his corporate fans. But Blink is a muddle. Gladwell's considerable ability to tell stories and distil research is intact, but applied to intractable, even contradictory material. The first anecdote, about a fake kouros acquired by the Getty Museum, shows sensitive art experts recoiling instinctively from the phony kouros, even as stolid scientists insist it is the genuine article. Gladwell has you infer that a two-second hunch can tell you more than months of scientific analysis. A flattering thought, but surely an utterly misleading one, given that the people having sudden, insightful hunches about the kouros were not ignoramuses, but eminent art historians with years of kouros-examining experience behind them.

Another tale, of psychologists accurately predicting divorce in newlyweds they had filmed for only three minutes is, at first glance, more persuasive. Because three minutes are involved here, rather than two seconds, Gladwell has to introduce an additional bit of quick-thinking jargon called "thin slicing". Which means "the ability of our unconscious to find patterns in situations and behaviour based on very narrow slices of experience". (I could be wrong, but feel - blink! - that the expression sounds too ham/slicer/delicatessen-related to really catch on). But this particular three-minute slice had been carefully designed by experienced behavioural psychologists to expose marital discord. The US divorce rate, when these psychologists were predicting divorce, varied between 0.48% and 0.41% per capita.

The more examples Gladwell adduces of first impressions calculated to turn out right, and then of other ones that come out badly wrong - such as the time an innocent man was shot by panicking police officers - the more his big point gets buried under a heap of caveats and conditions and provisos. Contrary to any impression formed in the first chapter, it appears that Gladwell is not going to teach us how to intuit things at top speed, like the kouros-shudderers. Instead we learn that "truly successful decision making relies on a balance between deliberate and instinctive thinking". A final story, about musicians being auditioned behind screens, is a cautionary tale about not judging by appearances. It leads Gladwell to advise against the very practice he started off selling: "Too often," he says, "we are resigned to what happens in the blink of an eye."

A warning which may leave your snap judgments, like recovering Atkins dieters, in worse shape than they were when you started. Still, study the small print and there's no chance of your money back: "snap judgments and first impressions can be educated and controlled," Gladwell wrote, in his introduction. He never said he'd help us "become better decision-makers in our homes, offices and everyday life". That was his publisher, on the book-jacket. No wonder the marketing world adores him.